Offline Mode - No Login after Windows lock possible

Hi,
currently we are trying the latest public beta 13.5.9.0 and we are facing a problem:

1. Start RDM
2. Choose the datasource mariadb and click on offline
3. everything loads and works
4. Lock your windows machine with win + l
5. after login back to windows RDM is hidden in the tray icon
6. double click on the tray icon, a login window appears
7. no chance to enter a username (it's greyed out)
8. password is not working
9. have to kill RDM with task manager
10. restart RDM

Can you please have a look at this?

Thank you